Vion from Avdira lived during the end of the 5h and the beginnings of the 4th century B.C. (about 430 -370 B.C.). He was an astrologist, a meteorologist, a mathematician and a philosopher. He was also a student of Democritus and wrote in Attic and Ionian dialect. According to Diogenes from Laerti, Vion from Avdira was the first who talked about the theory of areas of the earth where there is only day for six months and only night for the other six months of the year. This fact reveals that he imagined earth as spherical in shape. Additionally, Vion tried to connect the direction of the winds with the climate. His theories and scientific views lead us to the fact that he traveled a lot in distant areas.